The XMASS experiment...2014/06/25 · IDM 2014 1 Outline Introduction to XMASS Physics results from...
Transcript of The XMASS experiment...2014/06/25 · IDM 2014 1 Outline Introduction to XMASS Physics results from...
![Page 1: The XMASS experiment...2014/06/25 · IDM 2014 1 Outline Introduction to XMASS Physics results from commissioning data Light WIMPs Solar axions 129Xe inelastic scattering by WIMPs](https://reader035.fdocuments.net/reader035/viewer/2022071105/5fdf1c4d0081920b4963e225/html5/thumbnails/1.jpg)
The XMASS experimentKATSUKI HIRAIDE ( ICRR, THE UNIVERSITY OF TOKYO)
JUNE 25 TH, 2014
IDM 2014
1
![Page 2: The XMASS experiment...2014/06/25 · IDM 2014 1 Outline Introduction to XMASS Physics results from commissioning data Light WIMPs Solar axions 129Xe inelastic scattering by WIMPs](https://reader035.fdocuments.net/reader035/viewer/2022071105/5fdf1c4d0081920b4963e225/html5/thumbnails/2.jpg)
Outline Introduction to XMASS
Physics results from commissioning data Light WIMPs
Solar axions
129Xe inelastic scattering by WIMPs
Bosonic super-WIMPs
Detector refurbishment and current status
Future prospects
2
![Page 3: The XMASS experiment...2014/06/25 · IDM 2014 1 Outline Introduction to XMASS Physics results from commissioning data Light WIMPs Solar axions 129Xe inelastic scattering by WIMPs](https://reader035.fdocuments.net/reader035/viewer/2022071105/5fdf1c4d0081920b4963e225/html5/thumbnails/3.jpg)
The XMASS experiment
3
Xenon detector for Weakly Interacting MASSive Particles (dark matter) Xenon MASSive detector for solar neutrino (pp/7Be solar neutrino) Xenon neutrino MASS detector (double beta decay)
Proposed as a multi purpose experiment with liquid Xenon
Low energy threshold Sensitive to e/g events as well as nuclear recoil
Large target mass and its scalability
WIMPs (by elastic and 129Xe inelastic scattering),Solar axions, Bosonic super-WIMPs,Supernova neutrino burst, double electron capture, …
XMASS-1(total ~1ton)
XMASS-1.5(total ~5tons)
XMASS-2(total ~24tons)
![Page 4: The XMASS experiment...2014/06/25 · IDM 2014 1 Outline Introduction to XMASS Physics results from commissioning data Light WIMPs Solar axions 129Xe inelastic scattering by WIMPs](https://reader035.fdocuments.net/reader035/viewer/2022071105/5fdf1c4d0081920b4963e225/html5/thumbnails/4.jpg)
The XMASS collaboration
4
Kamioka Observatory, ICRR, the University of Tokyo: K. Abe, K. Hiraide, K. Ichimura, Y. Kishimoto, K. Kobayashi, M. Kobayashi,S. Moriyama, M. Nakahata, T. Norita, H. Ogawa, H. Sekiya, O. Takachio, A. Takeda, M. Yamashita, B. Yang
Kavli IPMU, the University of Tokyo: J.Liu, K.Martens, Y. SuzukiKobe University: R. Fujita, K. Hosokawa, K. Miuchi, Y. Ohnishi, N. Oka, Y. TakeuchiTokai University: K. NishijimaGifu University: S. TasakaYokohama National University: S. NakamuraMiyagi University of Education: Y. FukudaSTEL, Nagoya University: Y. Itow, R. Kegasa, K. Kobayashi, K. Masuda, H. TakiyaSejong University: N. Y. Kim, Y. D. KimKRISS: Y. H. Kim, M. K. Lee, K. B. Lee, J. S. Lee
June 2014
10 institutes~40 physicists
![Page 5: The XMASS experiment...2014/06/25 · IDM 2014 1 Outline Introduction to XMASS Physics results from commissioning data Light WIMPs Solar axions 129Xe inelastic scattering by WIMPs](https://reader035.fdocuments.net/reader035/viewer/2022071105/5fdf1c4d0081920b4963e225/html5/thumbnails/5.jpg)
History of XMASS-1 Sep. 2010: Detector construction completed.
Dec. 2010 – May. 2012: Commissioning data-taking
Aug. 2012 – Oct. 2013: Detector refurbishment
Nov. 2013 : data-taking resumed.
5
![Page 6: The XMASS experiment...2014/06/25 · IDM 2014 1 Outline Introduction to XMASS Physics results from commissioning data Light WIMPs Solar axions 129Xe inelastic scattering by WIMPs](https://reader035.fdocuments.net/reader035/viewer/2022071105/5fdf1c4d0081920b4963e225/html5/thumbnails/6.jpg)
The XMASS-1 detector
6
11
m
10m
Located in the Kamioka mine in Japan(~2,700m water equivalent)
A single-phase detectoremploying ~830kg of liquid xenon
Equipped with 642 PMTs
Active water shield
![Page 7: The XMASS experiment...2014/06/25 · IDM 2014 1 Outline Introduction to XMASS Physics results from commissioning data Light WIMPs Solar axions 129Xe inelastic scattering by WIMPs](https://reader035.fdocuments.net/reader035/viewer/2022071105/5fdf1c4d0081920b4963e225/html5/thumbnails/7.jpg)
Physics results from commissioning data
7
![Page 8: The XMASS experiment...2014/06/25 · IDM 2014 1 Outline Introduction to XMASS Physics results from commissioning data Light WIMPs Solar axions 129Xe inelastic scattering by WIMPs](https://reader035.fdocuments.net/reader035/viewer/2022071105/5fdf1c4d0081920b4963e225/html5/thumbnails/8.jpg)
Search for light WIMPs
8
Published in Phys. Lett. B 719 78 (2013)
6.7 days x 835 kg
0.3 keVee threshold
![Page 9: The XMASS experiment...2014/06/25 · IDM 2014 1 Outline Introduction to XMASS Physics results from commissioning data Light WIMPs Solar axions 129Xe inelastic scattering by WIMPs](https://reader035.fdocuments.net/reader035/viewer/2022071105/5fdf1c4d0081920b4963e225/html5/thumbnails/9.jpg)
Search for solar axions
9
Bremsstrahlung andCompton effect
gaee
Axio-electric effect
Published in Phys. Lett. B 724 46 (2013)
Axions can be produced in the sun by bremsstrahlung andCompton effect, and detected by axio-electric effect in XMASS.
Used the same data set as the light WIMPs search.
gaee
Out data
![Page 10: The XMASS experiment...2014/06/25 · IDM 2014 1 Outline Introduction to XMASS Physics results from commissioning data Light WIMPs Solar axions 129Xe inelastic scattering by WIMPs](https://reader035.fdocuments.net/reader035/viewer/2022071105/5fdf1c4d0081920b4963e225/html5/thumbnails/10.jpg)
Search for 129Xe inelastic scattering by WIMPs
10
Published in PTEP 063C01 (2014)
c + 129Xe c + 129Xe*129Xe* 129Xe + g (39.6keV)
Natural abundance of 129Xe: 26.4%
(1)= pre-selection
(2)= (1) & radius cut
(3)= (2) & timing cut
(4)= (3) & band cut
Observed data (165.9 days)Signal MC for 50GeV WIMP
Red: XMASS (90% C.L. stat. only)Pink band: XMASS (w/ sys. error)Black: DAMA LXe 2000 (90% C.L.)
Achieved ~3x10-4 dru @ a few 10’s keV
![Page 11: The XMASS experiment...2014/06/25 · IDM 2014 1 Outline Introduction to XMASS Physics results from commissioning data Light WIMPs Solar axions 129Xe inelastic scattering by WIMPs](https://reader035.fdocuments.net/reader035/viewer/2022071105/5fdf1c4d0081920b4963e225/html5/thumbnails/11.jpg)
Search for bosonic super-WIMPs
11
arXiv:1406.0502
Candidate for lighter dark matter Can be detected by absorption
of the particle, which is similarto the photoelectric effect.
Search for mono-energetic peakat the mass of the particle
v or a
Limits on pseudoscaler boson coupling are also obtained.
![Page 12: The XMASS experiment...2014/06/25 · IDM 2014 1 Outline Introduction to XMASS Physics results from commissioning data Light WIMPs Solar axions 129Xe inelastic scattering by WIMPs](https://reader035.fdocuments.net/reader035/viewer/2022071105/5fdf1c4d0081920b4963e225/html5/thumbnails/12.jpg)
Detector refurbishment and current status
12
![Page 13: The XMASS experiment...2014/06/25 · IDM 2014 1 Outline Introduction to XMASS Physics results from commissioning data Light WIMPs Solar axions 129Xe inelastic scattering by WIMPs](https://reader035.fdocuments.net/reader035/viewer/2022071105/5fdf1c4d0081920b4963e225/html5/thumbnails/13.jpg)
Detector refurbishment
13
High purity Al is vapored.
Al seal
After RFB
Al seal
Blind corner
Before RFB
Found RIs (210Pb, 238U) in the Aluminum seal of PMT. BG events at the blind corner of PMT are often misidentified as events in the fiducial volume. To reduce this background, new structures to cover this Al seal were installed.
![Page 14: The XMASS experiment...2014/06/25 · IDM 2014 1 Outline Introduction to XMASS Physics results from commissioning data Light WIMPs Solar axions 129Xe inelastic scattering by WIMPs](https://reader035.fdocuments.net/reader035/viewer/2022071105/5fdf1c4d0081920b4963e225/html5/thumbnails/14.jpg)
Photos of detector inner surface
14
Before refurbishment After refurbishment
![Page 15: The XMASS experiment...2014/06/25 · IDM 2014 1 Outline Introduction to XMASS Physics results from commissioning data Light WIMPs Solar axions 129Xe inelastic scattering by WIMPs](https://reader035.fdocuments.net/reader035/viewer/2022071105/5fdf1c4d0081920b4963e225/html5/thumbnails/15.jpg)
Data-taking with the refurbished detector
15
We resumed data-taking in Nov. 2013.
This time, 1GS/s flash-ADC was fullyintroduced to record waveforms of each PMT.
Took several calibration data usinggamma-ray and neutron sourcesto understand detector response.
Already accumulated 126 days datafor WIMP search.
![Page 16: The XMASS experiment...2014/06/25 · IDM 2014 1 Outline Introduction to XMASS Physics results from commissioning data Light WIMPs Solar axions 129Xe inelastic scattering by WIMPs](https://reader035.fdocuments.net/reader035/viewer/2022071105/5fdf1c4d0081920b4963e225/html5/thumbnails/16.jpg)
Current status
16
Energy spectra in entire volume(without position reconstruction) Understanding of detector response
Understanding of reconstruction performance Understanding of BG They are on-going
Quick check of BG in entire volumeOne order of magnitude reduction above 5 keVeefor entire volume achieved.
Results will come in near future
![Page 17: The XMASS experiment...2014/06/25 · IDM 2014 1 Outline Introduction to XMASS Physics results from commissioning data Light WIMPs Solar axions 129Xe inelastic scattering by WIMPs](https://reader035.fdocuments.net/reader035/viewer/2022071105/5fdf1c4d0081920b4963e225/html5/thumbnails/17.jpg)
Future: XMASS-1.5
17
PMTs for XMASS-1.5Scintillation light from
the surface can be detected.
PMTs for XMASS-IHigh probability to miss catching
the photons from the surface.
Dotted line = photo cathode Dotted curve = photo cathode
Red arrows: track of
scintillation photons
Total 5 tons of liquid xenon (with fiducial mass of 1 ton) Target sensitivity for sSI <10-46 cm2 for 100 GeV WIMPs Design of the detector is on-going
DAMA
CoGeNT
CDMS-Si
10-38
10-40
10-42
10-44
10-46
WIP
M-n
ucl
eon
cro
ss s
ecti
on
[cm
2]
10 102 103
WIMP mass (GeV)
![Page 18: The XMASS experiment...2014/06/25 · IDM 2014 1 Outline Introduction to XMASS Physics results from commissioning data Light WIMPs Solar axions 129Xe inelastic scattering by WIMPs](https://reader035.fdocuments.net/reader035/viewer/2022071105/5fdf1c4d0081920b4963e225/html5/thumbnails/18.jpg)
Summary Physics results from commissioning data Light WIMPs : Published in Phys. Lett. B 719 78 (2013)
Solar axions : Published in Phys. Lett. B 724 46 (2013)
129Xe inelastic scattering by WIMPs : Published in PTEP 063C01 (2014)
Bosonic super-WIMPs : arXiv:1406.0502
Current status Refurbishment of detector completed and data-taking resumed in Nov. 2013.
Results will come in near future.
Future Designing of XMASS-1.5 is on-going.
18
![Page 19: The XMASS experiment...2014/06/25 · IDM 2014 1 Outline Introduction to XMASS Physics results from commissioning data Light WIMPs Solar axions 129Xe inelastic scattering by WIMPs](https://reader035.fdocuments.net/reader035/viewer/2022071105/5fdf1c4d0081920b4963e225/html5/thumbnails/19.jpg)
Backup slides
19
![Page 20: The XMASS experiment...2014/06/25 · IDM 2014 1 Outline Introduction to XMASS Physics results from commissioning data Light WIMPs Solar axions 129Xe inelastic scattering by WIMPs](https://reader035.fdocuments.net/reader035/viewer/2022071105/5fdf1c4d0081920b4963e225/html5/thumbnails/20.jpg)
Calibration system
20OFCuRI source with holder adaptor(SUS304)
Source rod
RI sources
energy
[keV]
RI
[Hz]
φ [mm] package
(1) Fe-55 5.9 350 5 brass
(2) Cd-109 22, 25, 88 800 5 brass
(3) Am-241 59.5 485 0.15 SUS
(4) Co-57 122 100 0.21 SUS
Gate valve
Top PMT movingmachine
Source introduce machine
~5mXenon gas area
Top PMT(removed between calibration)
![Page 21: The XMASS experiment...2014/06/25 · IDM 2014 1 Outline Introduction to XMASS Physics results from commissioning data Light WIMPs Solar axions 129Xe inelastic scattering by WIMPs](https://reader035.fdocuments.net/reader035/viewer/2022071105/5fdf1c4d0081920b4963e225/html5/thumbnails/21.jpg)
Detector response for a point-like source
57Co source @ center gives a typical response ofthe detector.
photo electron yield 14.7p.e./keVee
The total pe and reconstructed vertex distributionswere reproduced by a simulation well.
real datasimulation
59.3keV of W
Reconstructed vertex distribution
21
57Co
122keV4%rmsW X ray
60keV
Real Data Simulation
21
Total photoelectron distribution
![Page 22: The XMASS experiment...2014/06/25 · IDM 2014 1 Outline Introduction to XMASS Physics results from commissioning data Light WIMPs Solar axions 129Xe inelastic scattering by WIMPs](https://reader035.fdocuments.net/reader035/viewer/2022071105/5fdf1c4d0081920b4963e225/html5/thumbnails/22.jpg)
Energy scale calibration
22
![Page 23: The XMASS experiment...2014/06/25 · IDM 2014 1 Outline Introduction to XMASS Physics results from commissioning data Light WIMPs Solar axions 129Xe inelastic scattering by WIMPs](https://reader035.fdocuments.net/reader035/viewer/2022071105/5fdf1c4d0081920b4963e225/html5/thumbnails/23.jpg)
Leff
23
![Page 24: The XMASS experiment...2014/06/25 · IDM 2014 1 Outline Introduction to XMASS Physics results from commissioning data Light WIMPs Solar axions 129Xe inelastic scattering by WIMPs](https://reader035.fdocuments.net/reader035/viewer/2022071105/5fdf1c4d0081920b4963e225/html5/thumbnails/24.jpg)
Trigger efficiency
24